The invention relates to a method for controlling a domestic appliance, in particular a washing machine or dishwasher for cleaning items of clothing and crockery respectively, when it is connected to at least one electric mains grid, which is especially branched off a public mains grid, within an individual household, the at least one electric mains grid being an intelligent system, such as a system allowing smart metering, so that measured power consumption is detected according to different consumption tariffs and information on the availability of a currently applicable consumption tariff or a switch-off condition for preventing peak loads in the mains grid is made available to the domestic appliance to be operated.
The invention also relates to a device, with which the method described above can be performed.
As background to the invention it has been identified that with new mains grids, which in particular allow smart metering, the economical operation of a domestic appliance, for example a washing machine or dishwasher, means that changes have to be made to the operation of said appliance, for example slowing down, speeding up and interruptions, which can significantly affect the result of the cleaning process of said appliance, if such influencing factors are not taken into account in some manner. In particular the cleaning action, which is based on the use of detergents or their individual components in the cleaning process, might be affected, as the detergents or their individual components are only able to allow their cleaning action to develop optimally, if they can be matched to specific temperatures and reaction and action times. Individual components, such as enzymes, in the detergent only have a very short life for example and require quite specific temperatures to have an optimum action.
Strategies are set out in DE 10 2008 062 349 A1 for domestic appliances, such as washing machines, dryers or dishwashers, in private households, which are operated on mains grids with smart metering, for how the domestic appliances can be operated price-optimally at times when the costs of drawing power are low but the domestic appliances according to the disclosure of this publication are only considered in respect of ohmic consumers of high output. The interruptions and resumptions of the operation of the domestic appliances according to this publication, as required by the focus on favorable consumption tariffs, are however not examined in respect of the cleaning result.
Intelligent power measurement or smart metering (digital power metering with extended functional scope) takes into account the fact that in future energy supply companies feeding into the public or their own mains grid, will be required to offer load-variable or time-based tariffs to their energy customers by way of their mains grids and to disseminate corresponding information in an appropriate manner. The power meters used up to now, for example Ferraris meters, will then no longer be used. However it should generally be considered that mains grids with integrated intelligence are also suitable for further aspects, such as a data exchange between energy customers and external service providers. It is also possible to optimize grid management by analyzing available data, especially from energy customers.
The use of such newly embodied mains grids, branched grids from which are present in a household, on which the generic domestic appliances are operated, means that the operation of the domestic appliances can be optimized in respect of available power tariffs. Washing and rinsing can therefore take place at low-tariff times. However it is also necessary to assume that there will be some very quick switches from high tariffs to low tariffs. However the domestic appliance should be operated mainly at low-tariff times,
As well as the new energy supply company grids, it is also necessary in a household to take account of domestic grids, which can be connected temporarily to the generic domestic appliances in addition to the public grids of the energy supply companies. The question of taking into account a lower tariff in each instance can also be important here.
The prior art also includes domestic appliances, such as washing machines, in which for each cleaning program the detergent is dosed by the operator introducing a quantity of detergent into the widely known detergent drawer at least not exclusively but with automatically controlled dosing of the detergent or components of the detergent taking place in addition or instead. The publication DE 10 2007 028 173 A1 provides for a storage facility for liquid or gel-type detergent components, to which a controllable dosing facility for the stored detergent components is connected. In the publication DE 100 62 111 C1 the absorption behavior of the laundry introduced into the laundry drum is determined for the automatic subsequent dosing of a liquid detergent present in a storage container external to the washing machine. In the publication DE 10 2008 042 655 A1 storage containers for liquid detergents or detergent components are provided within the actual housing of the domestic appliance, for example a washing machine, with electrically driven feed or immersion pumps projecting therein. A control unit, the principle of which is explained, serves to activate the feed pumps based on information supplied about soiling, load, type of laundry and the like, thereby dosing the detergent components optimally.